1. Technical Field
The present invention relates to an electronic timepiece configured to communicate data, to a communication device, and to a communication system.
2. Related Art
Electronic timepieces that use a solar cell to receive light and generate power, and receive optical signals transmitted from an external data transmission device are known from the literature. See, for example, JP-A-2001-99964.
When the electronic timepiece described in claim in JP-A-2001-99964 enters a data relay mode, it interrupts the charging path between the solar cell and the storage battery, detects the induced voltage of the solar cell while the charging path is interrupted, and evaluates the received signal by comparing the induced voltage with a reference voltage.
Because the charging path is always interrupted during data communication with the electronic timepiece in JP-A-2001-99964, the storage battery is not charged even when an optical signal is sent from an external data transmission device and the solar cell is exposed to light.
The capacity of the storage battery therefore drops if the storage battery is not charged because the electronic timepiece consumes power during data communication. This can result in data communication stopping due to insufficient power, which is not user friendly.